In co-pending U.S. application Ser. No. 129,831 filed Mar. 13, 1980, now U.S. Pat. No. 4,305,615, a Continuation-in-part of application Ser. No. 931,306 filed Mar. 7, 1978, now abandoned, a vehicle seat back mounting is disclosed having a pivotal connection with a bracket attached to the lower seat to accommodate forward tilting of the seat back for rear passenger entry and exit and a second adjustable pivot is provided to accommodate a reclined or otherwise adjusted back rest angle. An inertia latch is pivotally mounted on an intermediate bracket extending between the adjustment and forward tilting pivots with a recessed catch shaped for engaging a projection anchored on the stationary seat to prevent forward tilting. The center of gravity of the latch is located forwardly and below the pivot point so that during manual tilting of the seat back the force of gravity releases the latch from the projection and so that during sudden deceleration of the vehicle an inertial force counteracts the force of gravity and prevents unlatching.
Certain difficulties and limitations have been encountered with such inertial latch system which the present improved construction is directed to overcome. One problem arose when the seat back was tilted forward while in a reclined adjustment position due to lack of vehicle roof clearance for the extended length of the seat back when aligned with both adjustment and forward tilting pivots. Another problem arose when for any reason gravity failed to actuate the latch to permit forward tilting of the seat back with no convenient provision for manual release of the inertia latch. In addition, with the hook shaped catch of the depending inertia latch facing forward and the mass of the hook substantially rearward of the suspension pivot, a substantial mass of forwardly projecting extension of the inertia latch was required to provide a predominant counterbalancing center of gravity for the hook spaced horizontally sufficiently from the suspension pivot to provide effective gravity actuation to open the latch.